1. Field of the Invention
The present invention relates to a valve timing control device to be used for controlling the opening/closing timing of an intake valve or an exhaust valve in a valve actuating mechanism of an internal combustion engine.
2. Description of the Related Art
In Unexamined Published Japanese Patent Application No. Hei 1-92504 or Unexamined Published Japanese Utility Model Application No Hei 2-50105, for example, there is disclosed a valve timing control device, comprising a valve opening/closing rotary shaft rotatably assembled with the cylinder head of the internal combustion engine; a rotor integrally provided on the rotary shaft; a rotation transmitting member including a first mounting portion which is mounted around the peripheral surface of the rotor and a second mounting portion which is mounted around the peripheral surface of the rotary shaft, so as to rotate relative thereto within a predetermined range for transmitting rotating power from a crank pulley; a plurality of vanes provided on the rotor or the rotation transmitting member; a fluid chamber formed between the rotor and the rotation transmitting member and separated into advancing chambers and delaying chambers by the vanes; first fluid passages for feeding and discharging a fluid to and from the advancing chambers; and second fluid passages for feeding and discharging the fluid to and from the delaying chambers.
The valve timing control device, as described in each of the above-cited patent applications has both a first clearance and a second clearance. The first clearance is made between the first mounting portion of the rotation transmitting member and the peripheral surface of the rotor. The first clearance has influence on the amount of the fluid leaking from the fluid chamber. The second clearance is made between the second mounting portion of the rotation transmitting member and the peripheral surface of the rotary shaft. The second clearance has influence on making the rotation transmitting member and the rotary shaft positioned coaxially. In the above-mentioned valve timing control device, no consideration has been paid to the size of the clearances.
Thereby, it could be strong resistance at the first clearance and/or the second clearance, which is caused by the dimensions in the error range. The friction force between the rotation transmitting member and the rotary shaft may become bigger, if the error in the dimension of the rotational transmitting member and the rotary shaft was bigger in manufacturing